For some time, known toilets in which the toilet is flushed by flush water supplied from a flush water source to discharge waste have included, front elevation, those such as that set forth in Patent Document 1 (Japanese Patent Unexamined Publication No. 2014-34868), in which the adhesion surface between a body inner wall forming the majority of a bowl surface and a rim inner wall forming a portion of the bowl surface rises from the center region toward the front side region in the front-rear direction, and a rim conduit is formed on the upstream side of a rim spout port by adhesion of the body to the rim.
Also, as set forth in Patent Document 2 (Japanese Patent Unexamined Publication No. 2015-168994), flush toilets are known in which, for each of the conduits respectively formed on the upstream side of the two rim spout ports spouting flush water into the bowl, the bottom surface of the inlets thereof is positioned below the bottom surface of the outlet portion thereof.
However, in the above-described conventional flush toilet set forth in Patent Documents 1 and 2, water remaining in the rim conduit after completion of flush water spouting from the rim spout port is discharged from the rim spout port. However, because the time until this residual water stops is relatively long, there is a risk that a user viewing the residual water during discharge would mistake it for a leak. A further problem is that discharged residual water may remain on the bowl surface, or that residual water which has not been fully discharged may remain in the rim conduit.
In addition, with the diversification of flush toilet designs in recent years, there has been a growing need to plan for visual simplicity in the appearance of the toilet main unit bowl interior or the rim inside perimeter side, by placing items such as the rim spout port or the rim conduit relative to the rim so that the rim spout port or the upstream side rim conduit is invisible to the user side, and to design so that water is spouted rearward from the rim spout port. In such a form, where water is spouted rearward from a rim spout port, the rim conduit is formed in a limited space within the rim. The length of the flow path to obtain a flush water flow volume in the rim conduit is therefore set to be relatively long, and the size of the rim spout port to obtain a sufficient flush water flow speed (especially the rim spout port height dimension) is set to be relatively small.
Therefore in such a spouting form, in which water is spouted rearward from a rim spout port, the problem arises that the time until residual water stops lengthens as the flow path length used to achieve a specified flow volume in the rim conduit increases. Another problem is that the shorter the rim spout port height dimension used to obtain sufficient flush water flow speed, the more difficult it becomes to provide countermeasures to residual water, such as sloping the bottom surface of the rim conduit.
An issue has thus been how to increase the discharge force used to discharge residual water in the rim conduit from the rim spout port.